Your 'dynamic' solution at the moment is dead in the water.
It certainly does seem to be at MAN. But not at just about every other airport. And aircraft require all the same support services you mention at those. Everywhere else seems to be coping fine, and I don't think their staff are more handsomely remunerated than their Manchester counterparts.
MAN is uniquely FAILING in this respect, and that is a matter for concern. Repeated failure is unacceptable and should be addressed by management. But I see no urgency from MAG to address those areas of the operation which undermine the good work done by other departments at MAN. Reputation is always driven by those areas of the business which let the side down.
BTW, the 'tech' aircraft which you cite is exempt from any dynamic diversion decision-making process. A flight which declares an emergency CAN land. That's the rule. So the question of whether the airport operator would want to accept it or not is moot. And, of course, an aircraft which diverts in with a technical problem runs the risk of sticking around for a while. That's what 'tech' implies. If a non-emergency aircraft wishes to divert for technical reasons, that can be taken into consideration when a decision is made.